The Antares rocket, carrying an unmanned Cygnus resupply capsule packed with 3,293 lbs. of cargo, including food, science experiments and small satellites lifted off from Wallops at 12:52 ET.

Wallops' mission control reports that "the Cygnus spacecraft is safely on orbit with solar arrays deployed."

At a pre-launch briefing on Saturday, former NASA astronaut and Orbital Sciences CEO Frank Culbertson said the company was "real proud to be part of the team that is keeping the station flying and providing the crew with cargo and research they need."

"Orbital [Sciences], which is based in Dulles, Virginia, has a $1.9-billion contract with NASA to carry out eight cargo missions through 2016. Elon Musk's SpaceX, the only other commercial company with a NASA resupply contract, has been commissioned to fly 12 missions to the station under a $1.6 billion deal.

"The mission, dubbed Orb-2, was originally scheduled for May. It had been postponed due to conflicts with other launches and technical issues, including the failure of an AJ26 engine — the kind that powers Antares' first stage — during a test at NASA's Stennis Space Center in Mississippi, which prompted an investigation.

"Then this week, the mission was repeatedly delayed because stormy weather prevented Orbital's launch team from conducting normal operations to get the rocket ready on the pad."